To study the influencing factors of traffic violations,this study investigated the effects of vehicle attribution,day of week,time of day,location of traffic violations,and weather on traffic violations based on the e...To study the influencing factors of traffic violations,this study investigated the effects of vehicle attribution,day of week,time of day,location of traffic violations,and weather on traffic violations based on the electronic enforcement data and historical weather data obtained in Shangyu,China.Ten categories of traffic violations were determined from the raw data.Then,chi-square tests were used to analyze the relationship between traffic violations and the potential risk factors.Multinomial logistic regression analyses were conducted to further estimate the effects of different risk factors on the likelihood of the occurrence of traffic violations.By analyzing the results of chi-square tests via SPSS,the five factors above were all determined as significant factors associated with traffic violations.The results of the multinomial logistic regression revealed the significant effects of the five factors on the likelihood of the occurrence of corresponding traffic violations.The conclusions are of great significance for the development of effective traffic intervention measures to reduce traffic violations and the improvement of road traffic safety.展开更多
Clustering a social network is a process of grouping social actors into clusters where intra-cluster similarities among actors are higher than inter-cluster similarities. Clustering approaches, i.e. , k-medoids or hie...Clustering a social network is a process of grouping social actors into clusters where intra-cluster similarities among actors are higher than inter-cluster similarities. Clustering approaches, i.e. , k-medoids or hierarchical, use the distance function to measure the dissimilarities among actors. These distance functions need to fulfill various properties, including the triangle inequality (TI). However, in some cases, the triangle inequality might be violated, impacting the quality of the resulting clusters. With experiments, this paper explains how TI violates while performing traditional clustering techniques: k-medoids, hierarchical, DENGRAPH, and spectral clustering on social networks and how the violation of TI affects the quality of the resulting clusters.展开更多
To understand any statistical tool requires not only an understanding of the relevant computational procedures but also an awareness of the assumptions upon which the procedures are based, and the effects of violation...To understand any statistical tool requires not only an understanding of the relevant computational procedures but also an awareness of the assumptions upon which the procedures are based, and the effects of violations of these assumptions. In our earlier articles (Laverty, Miket, & Kelly [1]) and (Laverty & Kelly, [2] [3]) we used Microsoft Excel to simulate both a Hidden Markov model and heteroskedastic models showing different realizations of these models and the performance of the techniques for identifying the underlying hidden states using simulated data. The advantage of using Excel is that the simulations are regenerated when the spreadsheet is recalculated allowing the user to observe the performance of the statistical technique under different realizations of the data. In this article we will show how to use Excel to generate data from a one-way ANOVA (Analysis of Variance) model and how the statistical methods behave both when the fundamental assumptions of the model hold and when these assumptions are violated. The purpose of this article is to provide tools for individuals to gain an intuitive understanding of these violations using this readily available program.展开更多
A result from Kieffer, as outlined at the beginning of the article identifies two different candidates for initial time steps, delta t. We assert that this difference in time steps may be related to a specific early u...A result from Kieffer, as outlined at the beginning of the article identifies two different candidates for initial time steps, delta t. We assert that this difference in time steps may be related to a specific early universe Lorentz Violation. The author asserts that the existence of early universe Lorentz violation in turn is assisting in a breakup of primordial black holes. And that also has a tie into Kieffer different time steps as outlined. And the wrap up is given in the final part of this document.展开更多
For various reasons,many of the security programming rules applicable to specific software have not been recorded in official documents,and hence can hardly be employed by static analysis tools for detection.In this p...For various reasons,many of the security programming rules applicable to specific software have not been recorded in official documents,and hence can hardly be employed by static analysis tools for detection.In this paper,we propose a new approach,named SVR-Miner(Security Validation Rules Miner),which uses frequent sequence mining technique [1-4] to automatically infer implicit security validation rules from large software code written in C programming language.Different from the past works in this area,SVR-Miner introduces three techniques which are sensitive thread,program slicing [5-7],and equivalent statements computing to improve the accuracy of rules.Experiments with the Linux Kernel demonstrate the effectiveness of our approach.With the ten given sensitive threads,SVR-Miner automatically generated 17 security validation rules and detected 8 violations,5 of which were published by Linux Kernel Organization before we detected them.We have reported the other three to the Linux Kernel Organization recently.展开更多
Aiming at the problem that current geographical information systems(GIS)usually does not maintain semantic and user-defined constraints out of three consistency-constrains(third refers to topology constraint),this res...Aiming at the problem that current geographical information systems(GIS)usually does not maintain semantic and user-defined constraints out of three consistency-constrains(third refers to topology constraint),this research focuses on building an efficient spatial data management system using two constraint violation detection methods.An algorithm for constraint violation detection has been derived to maintain the error-free up-to-date spatial database.Results indicate that the developed constraint violation detection(CVD)system is more efficient compared with conventional systems.展开更多
The cloud service level agreement(SLA)manage the relationship between service providers and consumers in cloud computing.SLA is an integral and critical part of modern era IT vendors and communication contracts.Due to...The cloud service level agreement(SLA)manage the relationship between service providers and consumers in cloud computing.SLA is an integral and critical part of modern era IT vendors and communication contracts.Due to low cost and flexibility more and more consumers delegate their tasks to cloud providers,the SLA emerges as a key aspect between the consumers and providers.Continuous monitoring of Quality of Service(QoS)attributes is required to implement SLAs because of the complex nature of cloud communication.Many other factors,such as user reliability,satisfaction,and penalty on violations are also taken into account.Currently,there is no such policy of cloud SLA monitoring to minimize SLA violations.In this work,we have proposed a cloud SLA monitoring policy by dividing a monitoring session into two parts,for critical and non-critical parameters.The critical and non-critical parameters will be decided on the interest of the consumer during SLA negotiation.This will help to shape a new comprehensive SLA based Proactive Resource Allocation Approach(RPAA)which will monitor SLA at runtime,analyze the SLA parameters and try to find the possibility of SLA violations.We also have implemented an adaptive system for allocating cloud IT resources based on SLA violations and detection.We have defined two main components of SLA-PRAA i.e.,(a)Handler and(b)Accounting and Billing Manager.We have also described the function of both components through algorithms.The experimental results validate the performance of our proposed method in comparison with state-of-the-art cloud SLA policies.展开更多
There are some grammatical rules of pure syntactic restrictions on grammar rules of operation, a complex one of which is the fronting, i.e., extraction from the island. This paper centers on the ＂island＂ that is the...There are some grammatical rules of pure syntactic restrictions on grammar rules of operation, a complex one of which is the fronting, i.e., extraction from the island. This paper centers on the ＂island＂ that is the terminology in syntactic theory, and mainly focuses on the definition, the types and the analyses of the ＂island＂展开更多
Sustainable development requires overcoming opportunist behavior of economic entities towards environmental compartments.Another form of opportunist behavior is revealed in fraudulent financial reporting.The research ...Sustainable development requires overcoming opportunist behavior of economic entities towards environmental compartments.Another form of opportunist behavior is revealed in fraudulent financial reporting.The research objective is statistical comparison of environmental law violation against accounting abuses by Russian enterprises.A research hypothesis is put forward that companies,that violated environmental law,prepare financial reporting mostly incorrectly.An exploratory sampling from the economic entities of Russia,that violated environmental law in the course of various activities,was formed.Financial reporting of the sampling companies was analyzed by virtue of the authorial probit regression model,making it possible to reveal accounting misstatements,both overreporting and underreporting.The obtained results make it possible to assess the interrelations between the environmental law violations and financial reporting.展开更多
Asian Americans continue to face systemic discrimination in various aspects.A report released by the Alliance for Justice on May 22,2024,highlighted that for much ofthe 19th and20th centuries,Asian Americans were syst...Asian Americans continue to face systemic discrimination in various aspects.A report released by the Alliance for Justice on May 22,2024,highlighted that for much ofthe 19th and20th centuries,Asian Americans were systematically excluded from many areas of public life.Even today,41 state supreme courts have never had an Asian American judge,despite some ofthese states having significant Asian American populations.展开更多
August 2025,Foreword 2024,as an election year in the United States,was a year of special concern that features aggravating political strife and social divide.Such a landscape oflers an opportunity to review the state ...August 2025,Foreword 2024,as an election year in the United States,was a year of special concern that features aggravating political strife and social divide.Such a landscape oflers an opportunity to review the state of human rights in the country in an intensive manner。展开更多
This study investigates pedestrian crossing behaviors at signalized intersections,focusing on spatial and temporal violations.Using a comprehensive dataset comprising 5589 pedestrian crossing events at 47 crosswalks a...This study investigates pedestrian crossing behaviors at signalized intersections,focusing on spatial and temporal violations.Using a comprehensive dataset comprising 5589 pedestrian crossing events at 47 crosswalks across 39 intersections in Utah,the research employs multilevel regression models to identify the factors influencing these violation behaviors.Key findings indicate that individual characteristics such as gender and mobility device use,environmental conditions including temperature and time-of-day and social dynamics such as the presence of other pedestrians significantly impact violation behav-iors.The study reveals that female-presenting pedestrians and those using mobility devices are generally more compliant,while higher temperatures and specific times-of-day are associated with increased violation rates.The analysis also highlights that longer waiting time is linked to a reduced likelihood of violations,and that social dynamics play a crucial role,with the presence of other pedestrians discouraging violations.Additionally,neigh-borhoods with larger shares of Hispanic or non-white populations have higher violation rates,and mid-block crossings see more temporal violations.These findings aim to enhance pedestrian safety and compliance at signalized intersections,ultimately reducing pedes-trian fatalities and injuries.展开更多
Within the framework of the perturbative QCD approach utilizing k_(T)factorization,we investigated the CP violation and branching ratios in the decay processes of B_(c)^(+)→D_((s))^(+)V(V→π^(+)π^(−))and B_(c)^(+)...Within the framework of the perturbative QCD approach utilizing k_(T)factorization,we investigated the CP violation and branching ratios in the decay processes of B_(c)^(+)→D_((s))^(+)V(V→π^(+)π^(−))and B_(c)^(+)→D_((s))^(+)V(V→K^(+)K^(−)),where V denotes the three vector mesons ρ^(0),ω,and Ф.During the V→π^(+)π^(−) and V→K^(+)K^(−) decay processes,we incorporated the ρ^(0)-ω-Ф mixing mechanism to describe the amplitudes of these quasi-two-body decays.Within the interference region of the three vector particles,we observed distinct changes in both CP violations and branching ratios.Furthermore,our study presents evidence for local CP violations and branching ratios that warrants further experimental investigation.展开更多
We propose to deploy limits that arise from different tests of the Pauli Exclusion Principle： i） to provide theories of quantum gravity with experimental guidance; ii） to distinguish, among the plethora of possible...We propose to deploy limits that arise from different tests of the Pauli Exclusion Principle： i） to provide theories of quantum gravity with experimental guidance; ii） to distinguish, among the plethora of possible models, the ones that are already ruled out by current data; iii） to direct future attempts to be in accordance with experimental constraints. We first review experimental bounds on nuclear processes forbidden by the Pauli Exclusion Principle,which have been derived by several experimental collaborations making use of various detector materials. Distinct features of the experimental devices entail sensitivities on the constraints hitherto achieved that may differ from one another by several orders of magnitude. We show that with choices of these limits, well-known examples of flat noncommutative space-time instantiations of quantum gravity can be heavily constrained, and eventually ruled out.We devote particular attention to the analysis of the κ-Minkowski and θ-Minkowski noncommutative spacetimes.These are deeply connected to some scenarios in string theory, loop quantum gravity, and noncommutative geometry.We emphasize that the severe constraints on these quantum spacetimes, although they cannot rule out theories of top-down quantum gravity to which they are connected in various ways, provide a powerful limitation for those models. Focus on this will be necessary in the future.展开更多
This study aims to investigate Lorentz/U(1)gauge symmetry-breaking electrodynamics in the framework of the standard-model extension and analyze the Hamiltonian structure for the theory with a specific dimension of Lor...This study aims to investigate Lorentz/U(1)gauge symmetry-breaking electrodynamics in the framework of the standard-model extension and analyze the Hamiltonian structure for the theory with a specific dimension of Lorentz breaking operators.For this purpose,we consider a general quadratic action of the modified electrodynamics with Lorentz/gauge-breaking operators and calculate the number of independent components of the operators at different dimensions in gauge invariance and breaking.With this general action,we then analyze how Lorentz/gauge symmetry-breaking can change the Hamiltonian structure of the theories by considering Lorentz/gauge-breaking operators with dimension as examples.We show that the Lorentz-breaking operators with gauge invariance do not change the classes of the theory constrains and the number of physical degrees of freedom of the standard Maxwell electrodynamics.When U(1)gauge symmetry-breaking operators are present,the theories generally lack a first-class constraint and have one additional physical degree of freedom compared to the standard Maxwell electrodynamics.展开更多
We use a sample of Chinese A-share listed companies from 2003 to 2013 to explore the reputation damage and overflow effect of academic independent directors who have received supervisory punishment. We find that when ...We use a sample of Chinese A-share listed companies from 2003 to 2013 to explore the reputation damage and overflow effect of academic independent directors who have received supervisory punishment. We find that when companies violate information disclosure rules, the market punishes academic independent directors more severely than nonacademic independent directors for these violations. Furthermore, companies employing punished academic directors face greater declines in their stock price than companies employing punished nonacademic independent directors during a relatively short window before or after the punishment is announced. The punishment of academic independent directors influences the employment of other scholars in the same field and results in a negative overflow effect. This study provides evidence of the market's differential reactions to independent directors with different backgrounds; the findings reflect the double-edged sword of one individual's reputation on organizations.展开更多
With the rapid load increase in some countries such as China, power grids are becoming more strongly interconnected, and the differences between peak and valley loads are also increasing. As a result, some bulk power ...With the rapid load increase in some countries such as China, power grids are becoming more strongly interconnected, and the differences between peak and valley loads are also increasing. As a result, some bulk power systems are facing high voltage limit violations during light-load periods. This paper proposes to utilize transmission switching(TS) to eliminate voltage violations. The TS problem is formed as a mixed-integer nonlinear program(MINLP) with AC power flow constraints and binary variables. The proposed MINLP problem is non-deterministic polynomial hard.To efficiently solve the problem, a decomposition approach is developed. This approach decomposes the original problem into a mixedinteger linear programming master problem and an AC optimal power flow slave problem that is used to check the AC feasibility. Prevention of islanding is also taken into consideration to ensure the feasibility of the TS results.The modified IEEE 39-bus and IEEE 57-bus test systems are used to demonstrate the applicability and effectiveness of the proposed method.展开更多
In the framework of the QCD factorization approach,we study the localized CP violations of the B^(-)→K^(-)π^(+)(π)^(-)decay with and without the a_(0)^(0)(980)-f_(0)(980) mixing mechanism and observe that the local...In the framework of the QCD factorization approach,we study the localized CP violations of the B^(-)→K^(-)π^(+)(π)^(-)decay with and without the a_(0)^(0)(980)-f_(0)(980) mixing mechanism and observe that the localized CP violation can be enhanced by this mixing effect when the mass of the π^(+)(π)^(-)pair is in the vicinity of the f_(0)(980) resonance.The corresponding theoretical prediction results are A_(CP)(B^(-)→Kf_(0)→K^(-)π^(+)(π)^(-))=[0.126,0.338](0.232±0.106 with the central value form) and A_(CP)(B^(-)→K^(-)f_(0)(a_0)→K^(-)π^(+)(π)^(-))=[0.230,0.615](0.423±0.193 with the central value form),respectively.Meanwhile,we also calculate the branching fraction of the B^(-)→K^(-)f_(0)(980)→K^(-)π^(+)(π)^(-)decay,which is consistent with the experimental results.We suggest that the a_(0)^(0)(980)-f_(0)(980) mixing mechanism should be considered when theoretically and experimentally studying the CP violation of the B or D meson decays.展开更多
基金The National Key Research and Development Program of China(No.2019YFB1600200).
文摘To study the influencing factors of traffic violations,this study investigated the effects of vehicle attribution,day of week,time of day,location of traffic violations,and weather on traffic violations based on the electronic enforcement data and historical weather data obtained in Shangyu,China.Ten categories of traffic violations were determined from the raw data.Then,chi-square tests were used to analyze the relationship between traffic violations and the potential risk factors.Multinomial logistic regression analyses were conducted to further estimate the effects of different risk factors on the likelihood of the occurrence of traffic violations.By analyzing the results of chi-square tests via SPSS,the five factors above were all determined as significant factors associated with traffic violations.The results of the multinomial logistic regression revealed the significant effects of the five factors on the likelihood of the occurrence of corresponding traffic violations.The conclusions are of great significance for the development of effective traffic intervention measures to reduce traffic violations and the improvement of road traffic safety.
文摘Clustering a social network is a process of grouping social actors into clusters where intra-cluster similarities among actors are higher than inter-cluster similarities. Clustering approaches, i.e. , k-medoids or hierarchical, use the distance function to measure the dissimilarities among actors. These distance functions need to fulfill various properties, including the triangle inequality (TI). However, in some cases, the triangle inequality might be violated, impacting the quality of the resulting clusters. With experiments, this paper explains how TI violates while performing traditional clustering techniques: k-medoids, hierarchical, DENGRAPH, and spectral clustering on social networks and how the violation of TI affects the quality of the resulting clusters.
文摘To understand any statistical tool requires not only an understanding of the relevant computational procedures but also an awareness of the assumptions upon which the procedures are based, and the effects of violations of these assumptions. In our earlier articles (Laverty, Miket, & Kelly [1]) and (Laverty & Kelly, [2] [3]) we used Microsoft Excel to simulate both a Hidden Markov model and heteroskedastic models showing different realizations of these models and the performance of the techniques for identifying the underlying hidden states using simulated data. The advantage of using Excel is that the simulations are regenerated when the spreadsheet is recalculated allowing the user to observe the performance of the statistical technique under different realizations of the data. In this article we will show how to use Excel to generate data from a one-way ANOVA (Analysis of Variance) model and how the statistical methods behave both when the fundamental assumptions of the model hold and when these assumptions are violated. The purpose of this article is to provide tools for individuals to gain an intuitive understanding of these violations using this readily available program.
文摘A result from Kieffer, as outlined at the beginning of the article identifies two different candidates for initial time steps, delta t. We assert that this difference in time steps may be related to a specific early universe Lorentz Violation. The author asserts that the existence of early universe Lorentz violation in turn is assisting in a breakup of primordial black holes. And that also has a tie into Kieffer different time steps as outlined. And the wrap up is given in the final part of this document.
基金National Natural Science Foundation of China under Grant No.60873213,91018008 and 61070192Beijing Science Foundation under Grant No. 4082018Shanghai Key Laboratory of Intelligent Information Processing of China under Grant No. IIPL-09-006
文摘For various reasons,many of the security programming rules applicable to specific software have not been recorded in official documents,and hence can hardly be employed by static analysis tools for detection.In this paper,we propose a new approach,named SVR-Miner(Security Validation Rules Miner),which uses frequent sequence mining technique [1-4] to automatically infer implicit security validation rules from large software code written in C programming language.Different from the past works in this area,SVR-Miner introduces three techniques which are sensitive thread,program slicing [5-7],and equivalent statements computing to improve the accuracy of rules.Experiments with the Linux Kernel demonstrate the effectiveness of our approach.With the ten given sensitive threads,SVR-Miner automatically generated 17 security validation rules and detected 8 violations,5 of which were published by Linux Kernel Organization before we detected them.We have reported the other three to the Linux Kernel Organization recently.
文摘Aiming at the problem that current geographical information systems(GIS)usually does not maintain semantic and user-defined constraints out of three consistency-constrains(third refers to topology constraint),this research focuses on building an efficient spatial data management system using two constraint violation detection methods.An algorithm for constraint violation detection has been derived to maintain the error-free up-to-date spatial database.Results indicate that the developed constraint violation detection(CVD)system is more efficient compared with conventional systems.
文摘The cloud service level agreement(SLA)manage the relationship between service providers and consumers in cloud computing.SLA is an integral and critical part of modern era IT vendors and communication contracts.Due to low cost and flexibility more and more consumers delegate their tasks to cloud providers,the SLA emerges as a key aspect between the consumers and providers.Continuous monitoring of Quality of Service(QoS)attributes is required to implement SLAs because of the complex nature of cloud communication.Many other factors,such as user reliability,satisfaction,and penalty on violations are also taken into account.Currently,there is no such policy of cloud SLA monitoring to minimize SLA violations.In this work,we have proposed a cloud SLA monitoring policy by dividing a monitoring session into two parts,for critical and non-critical parameters.The critical and non-critical parameters will be decided on the interest of the consumer during SLA negotiation.This will help to shape a new comprehensive SLA based Proactive Resource Allocation Approach(RPAA)which will monitor SLA at runtime,analyze the SLA parameters and try to find the possibility of SLA violations.We also have implemented an adaptive system for allocating cloud IT resources based on SLA violations and detection.We have defined two main components of SLA-PRAA i.e.,(a)Handler and(b)Accounting and Billing Manager.We have also described the function of both components through algorithms.The experimental results validate the performance of our proposed method in comparison with state-of-the-art cloud SLA policies.
文摘There are some grammatical rules of pure syntactic restrictions on grammar rules of operation, a complex one of which is the fronting, i.e., extraction from the island. This paper centers on the ＂island＂ that is the terminology in syntactic theory, and mainly focuses on the definition, the types and the analyses of the ＂island＂
文摘Sustainable development requires overcoming opportunist behavior of economic entities towards environmental compartments.Another form of opportunist behavior is revealed in fraudulent financial reporting.The research objective is statistical comparison of environmental law violation against accounting abuses by Russian enterprises.A research hypothesis is put forward that companies,that violated environmental law,prepare financial reporting mostly incorrectly.An exploratory sampling from the economic entities of Russia,that violated environmental law in the course of various activities,was formed.Financial reporting of the sampling companies was analyzed by virtue of the authorial probit regression model,making it possible to reveal accounting misstatements,both overreporting and underreporting.The obtained results make it possible to assess the interrelations between the environmental law violations and financial reporting.
文摘Asian Americans continue to face systemic discrimination in various aspects.A report released by the Alliance for Justice on May 22,2024,highlighted that for much ofthe 19th and20th centuries,Asian Americans were systematically excluded from many areas of public life.Even today,41 state supreme courts have never had an Asian American judge,despite some ofthese states having significant Asian American populations.
文摘August 2025,Foreword 2024,as an election year in the United States,was a year of special concern that features aggravating political strife and social divide.Such a landscape oflers an opportunity to review the state of human rights in the country in an intensive manner。
基金supported by the Utah Department of Transportation(UDOT).
文摘This study investigates pedestrian crossing behaviors at signalized intersections,focusing on spatial and temporal violations.Using a comprehensive dataset comprising 5589 pedestrian crossing events at 47 crosswalks across 39 intersections in Utah,the research employs multilevel regression models to identify the factors influencing these violation behaviors.Key findings indicate that individual characteristics such as gender and mobility device use,environmental conditions including temperature and time-of-day and social dynamics such as the presence of other pedestrians significantly impact violation behav-iors.The study reveals that female-presenting pedestrians and those using mobility devices are generally more compliant,while higher temperatures and specific times-of-day are associated with increased violation rates.The analysis also highlights that longer waiting time is linked to a reduced likelihood of violations,and that social dynamics play a crucial role,with the presence of other pedestrians discouraging violations.Additionally,neigh-borhoods with larger shares of Hispanic or non-white populations have higher violation rates,and mid-block crossings see more temporal violations.These findings aim to enhance pedestrian safety and compliance at signalized intersections,ultimately reducing pedes-trian fatalities and injuries.
基金Supported by Natural Science Foundation of Henan(252300420319)National Natural Science Foundation of China(12275024).
文摘Within the framework of the perturbative QCD approach utilizing k_(T)factorization,we investigated the CP violation and branching ratios in the decay processes of B_(c)^(+)→D_((s))^(+)V(V→π^(+)π^(−))and B_(c)^(+)→D_((s))^(+)V(V→K^(+)K^(−)),where V denotes the three vector mesons ρ^(0),ω,and Ф.During the V→π^(+)π^(−) and V→K^(+)K^(−) decay processes,we incorporated the ρ^(0)-ω-Ф mixing mechanism to describe the amplitudes of these quasi-two-body decays.Within the interference region of the three vector particles,we observed distinct changes in both CP violations and branching ratios.Furthermore,our study presents evidence for local CP violations and branching ratios that warrants further experimental investigation.
文摘We propose to deploy limits that arise from different tests of the Pauli Exclusion Principle： i） to provide theories of quantum gravity with experimental guidance; ii） to distinguish, among the plethora of possible models, the ones that are already ruled out by current data; iii） to direct future attempts to be in accordance with experimental constraints. We first review experimental bounds on nuclear processes forbidden by the Pauli Exclusion Principle,which have been derived by several experimental collaborations making use of various detector materials. Distinct features of the experimental devices entail sensitivities on the constraints hitherto achieved that may differ from one another by several orders of magnitude. We show that with choices of these limits, well-known examples of flat noncommutative space-time instantiations of quantum gravity can be heavily constrained, and eventually ruled out.We devote particular attention to the analysis of the κ-Minkowski and θ-Minkowski noncommutative spacetimes.These are deeply connected to some scenarios in string theory, loop quantum gravity, and noncommutative geometry.We emphasize that the severe constraints on these quantum spacetimes, although they cannot rule out theories of top-down quantum gravity to which they are connected in various ways, provide a powerful limitation for those models. Focus on this will be necessary in the future.
基金Supported by the National Key Research and Development Program of China(2020YFC2201503)the Zhejiang Provincial Natural Science Foundation of China(LR21A050001,LY20A050002)+1 种基金the National Natural Science Foundation of China(12275238,11675143)B.-F.Li is supported by the National Natural Science Foundation of China(NNSFC)(12005186)。
文摘This study aims to investigate Lorentz/U(1)gauge symmetry-breaking electrodynamics in the framework of the standard-model extension and analyze the Hamiltonian structure for the theory with a specific dimension of Lorentz breaking operators.For this purpose,we consider a general quadratic action of the modified electrodynamics with Lorentz/gauge-breaking operators and calculate the number of independent components of the operators at different dimensions in gauge invariance and breaking.With this general action,we then analyze how Lorentz/gauge symmetry-breaking can change the Hamiltonian structure of the theories by considering Lorentz/gauge-breaking operators with dimension as examples.We show that the Lorentz-breaking operators with gauge invariance do not change the classes of the theory constrains and the number of physical degrees of freedom of the standard Maxwell electrodynamics.When U(1)gauge symmetry-breaking operators are present,the theories generally lack a first-class constraint and have one additional physical degree of freedom compared to the standard Maxwell electrodynamics.
基金financial support from the National Natural Science Foundation of China(Project Nos.7160219171502174)the Special Funds for the Fundamental Scientific Research of Central Universities of Zhongnan University of Economics and Law
文摘We use a sample of Chinese A-share listed companies from 2003 to 2013 to explore the reputation damage and overflow effect of academic independent directors who have received supervisory punishment. We find that when companies violate information disclosure rules, the market punishes academic independent directors more severely than nonacademic independent directors for these violations. Furthermore, companies employing punished academic directors face greater declines in their stock price than companies employing punished nonacademic independent directors during a relatively short window before or after the punishment is announced. The punishment of academic independent directors influences the employment of other scholars in the same field and results in a negative overflow effect. This study provides evidence of the market's differential reactions to independent directors with different backgrounds; the findings reflect the double-edged sword of one individual's reputation on organizations.
文摘With the rapid load increase in some countries such as China, power grids are becoming more strongly interconnected, and the differences between peak and valley loads are also increasing. As a result, some bulk power systems are facing high voltage limit violations during light-load periods. This paper proposes to utilize transmission switching(TS) to eliminate voltage violations. The TS problem is formed as a mixed-integer nonlinear program(MINLP) with AC power flow constraints and binary variables. The proposed MINLP problem is non-deterministic polynomial hard.To efficiently solve the problem, a decomposition approach is developed. This approach decomposes the original problem into a mixedinteger linear programming master problem and an AC optimal power flow slave problem that is used to check the AC feasibility. Prevention of islanding is also taken into consideration to ensure the feasibility of the TS results.The modified IEEE 39-bus and IEEE 57-bus test systems are used to demonstrate the applicability and effectiveness of the proposed method.
基金Supported by National Natural Science Foundation of China (12105149,11775024 and 11947001)Natural Science Foundation of Zhejiang Province(LQ21A050005)+1 种基金Ningbo Natural Science Foundation (2021J180)the Fundamental Research Funds for the Provincial Universities of Zhejiang Province。
文摘In the framework of the QCD factorization approach,we study the localized CP violations of the B^(-)→K^(-)π^(+)(π)^(-)decay with and without the a_(0)^(0)(980)-f_(0)(980) mixing mechanism and observe that the localized CP violation can be enhanced by this mixing effect when the mass of the π^(+)(π)^(-)pair is in the vicinity of the f_(0)(980) resonance.The corresponding theoretical prediction results are A_(CP)(B^(-)→Kf_(0)→K^(-)π^(+)(π)^(-))=[0.126,0.338](0.232±0.106 with the central value form) and A_(CP)(B^(-)→K^(-)f_(0)(a_0)→K^(-)π^(+)(π)^(-))=[0.230,0.615](0.423±0.193 with the central value form),respectively.Meanwhile,we also calculate the branching fraction of the B^(-)→K^(-)f_(0)(980)→K^(-)π^(+)(π)^(-)decay,which is consistent with the experimental results.We suggest that the a_(0)^(0)(980)-f_(0)(980) mixing mechanism should be considered when theoretically and experimentally studying the CP violation of the B or D meson decays.
